Apparatus for connecting a lift assembly to a fork lift truck



Jan. 28, 1969 A- J. GIDEONSEN ET AL APPARATUS FOR CONNECTING A LIFT ASSEMBLY TO A FORK LIFT TRUCK Sheet of 2 Filed March 6, 1967 INVENTORS ARTHUR J. GIDEONSEN DALE D. SANDROCK 9'; l ATTORNEYS Jan. 28, 1969 A. J. GIDE ONSEN ET AL 3,424,328

APPARATUS FOR CONNECTING A LIFT ASSEMBLY TO A FORK LIFT TRUCK Filed March 6, 1967 Sheet 2 of 2 P1E E INVENTORS ARTHUR J: GIDEONSEN DALE D. SANDROCK Wfl, www

ATTORNEYS United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE A fork lift having a lift assembly adapted for oscillation about two normally related axes. Universal pivot means for connecting a lift assembly to a fork lift frame and means for controlling oscillation of the fork lift assembly with respect to the frame about two normally related axes.

Background of the invention The present invention relates to fork lifts and more particularly to rough terrain fork lift vehicles having a fork lift assembly mounted on the front thereof for bi-axial oscillation with respect to the vehicle. In such vehicles, it is desirable to oscillate or cant the fork lift assembly about a longitudinal axis of the vehicle for insertion of the fork tines under canted loads and for horizontal carrying of a load while the vehicle is traveling on a side slope. It is further desirable to oscillate or tilt the fork lift assembly about a second horizontal axis normal to the vehicu lar longitudinal axis to further facilitate loading or unloading of the fork lift assembly. Common prior art fork lift vehicles empolyed a fork lift assembly affixed to a fork lift frame by means of a first uni-axial pivot point for tilting oscillation of the fork lift assembly. A structurally separate second pivot means was then provided in the fork lift assembly, frame or even in the vehicle itself to permit canting oscillation of at least a part of the fork lift assembly about the longitudinal axis of the vehicle. The oscillation of the fork lift assembly about both above axes was controlled by chain, gear or pulley drives or by hydraulic jacks. Such fork lift vehicles resulted in oscillation linkages between the fork lift assembly and the fork lift vehicle or frame which were mechanically complicated and required numerous components. Accordingly, such linkages were relatively expensive to construct or maintain and further resulted in a noncompact structure.

Summary of the invention The present invention provides a compact and mechanically simple lift assembly linkage to the fork lift. Universal pivot 'means connect the lift assembly and the fork lift frame. Control means are provided for oscillation of the lift assembly with respect to the fork lift frame and vehicle about two normally related axes through the single pivot means.

Brief description of the drawing FIG. 1 is an assembly illustration of a preferred embodiment of the present invention including bi-axial pivot means for connecting a fork lift frame with a fork lift assembly.

FIG. 2 is a fragmentary view of an alternate embodiment wherein spherical connecting means are employed between the fork lift assembly and the frame.

Description of the preferred embodiments Referring now to FIG. 1, the present fork lift apparatus comprises a fork lift frame 11 of a type generally projecting forwardly from a fork lift vehicle (not shown). Universal pivot means 12 projects forwardly from frame 11 to Patented Jan. 28, 1969 serve as a connection between frame 11 and fork tine lift assembly 13. Lift assembly 13 includes fork tines 14 and 16 which move transversely across lift assembly 13 according to side shifting mechanism 17.

To control clockwise or counterclockwise canting of lift assembly 13, i.e., about a longitudinal axis of frame 11 and pivot means 12, double-acting hydraulic jacks 18 and 19 are vertically disposed on either side of pivot means 12 and are each pivotally disposed between pivotal connectors 21 and 22 of frame 11 and similar connectors 23 and 24 of lift assembly 13. To control forward and backward tilting of lift assembly 13, i.e., about a transverse axis through pivot means 12, longitudinally disposed double-acting hydraulic jack 26 is disposed between pin connector 27 of frame 11 and a pivotal connector 28 of lift assembly 13.

To permit the above described bi-axial oscillation of lift assembly 13 with respect to frame 11, universal pivot means 12 comprises bi-axial pivot pin 29 longitudinally and rotatably disposed with respect to frame 11 upon bearing surface 31 of forward transverse member 32 of frame 11. End 33 of pivot pin 29 projects forwardly from frame transverse member 32 and defines cylindrical pin connecting means 34 normally disposed with respect to the longitudinal axis of frame 11 and pin 29. Lift assembly 13 is connected to frame 11 by a pin 35 rotatably disposed in pin connecting means 34.

Preferably hydraulic jacks 18, 19 and 26 and their respective rods 36, 37 and 38 are connected to frame 11 and lift assemblies through bi-axialy pivotal connections to reduce mechanical wear in the connection due to the bi-axial oscillation of lift assembly 13.

To cant lift assembly 13 in either a clockwise or counterclockwise direction, rod 36 is extended by hydraulic jack 18 while rod 37 is retracted by hydraulic jack 19 or vice .versa. Similarly, to tilt lift assembly 13 either forwardly or backwardly, rod 38 is either extended or retracted by hydraulic jack 26. Thus the above embodiment provides single bi-axial pivot means 12 of economical and reliable construction, which permits bi-axial oscillation of lift assembly 13 with respect to frame 11.

With reference to FIG. 2, a second embodiment comprises fork lift assembly base plate 111 which is connected to fork lift frame 112 for bi-axial oscillation with respect thereto by universal pivot means 113 in the form of'a spherical connection. Frame 112 is similar to frame 11 of FIG. 1. Pork lift base plate 111 is representative of a fork lift assembly similar to assembly 13 of FIG. 1. Disposition and operation of hydraulic jacks 114, 116 and 117 for canting or tilting of the fork lift assembly represented by base plate 111 with respect to frame 112 is similar as in the above description with respect to hydraulic jacks 18, 19 and 26.

Universal pivot means 113 preferably comprises a spherical mounting 118 disposed between spaced apart mounting arms 119 and 121 projecting forwardly from a central portion of tubular transverse member 122 of frame 112. Base plate 111 has a connector 123 projecting rearwardly from a generally central portion thereof. Rearward facing surface 124 of connector 123 defines a spherical socket 126 to mate with and oscillate at least bi-axially with respect to spherical mounting 118. To maintain connector 123 in mating relation with mounting 118, cap 127 is spherically indented to mate with spherical mount 118 and is affixed to connector 123, e.g., by bolts passing through cap 127 and into threaded bores of connector 123.

To prevent lift assembly oscillation about a generally vertical axis through spherical mounts 118, Le, horizontal swing of assembly 13, and to generally stabilize the lift assembly connection to frame 112, Wear plates 128 and 129 are forwardly disposed on lateral extremities of transverse frame member 122. Base plate 111 has bumpers 131 and 132 projecting rearwardly therefrom to slidably engage with wear plates 128 and 129, respectively and thus stabilize lift assembly 13.

As discussed supra, forward and backward tilting as well as clockwise and counterclockwise canting of the lift assembly represented by base plate 111 is accomplished by operation of hydraulic jacks 114, 116 and 117. Thus bi-axial oscillation of a fork lift assembly, either in canting or tilting motion, is accomplished through single pivot means 113. It is noted that the shape and disposition of connector 123, cap 127 and mounting arms 119 and 121 tend to restrict the canting oscillation of base plate 111. The above alternate embodiment was designed to permit 10 of sidewise canting oscillation in either clockwise or counterclockwise rotation from a horizontal fork lift assembly position. The configuration of the above noted components may readily be altered to permit an increased degree of oscillation.

Q What is claimed is:

1. In a fork lift mechanism having a fork lift assembly and a frame to which the fork lift assembly is connected for bi-axial oscillation with relation thereto, the apparatus comprising:

universal pivot means connecting the fork lift assembly and fork lift frame and permitting oscillation of the lift assembly relative to the frame about two intersecting and normally related axes which pass through said universal pivot means; and

means for controlling oscillation of the lift assembly with respect to the frame about the two axes.

2. A fork lift mechanism according to claim 1 wherein said pivot means is a bi-axial pivot pin mounted on a bearing surface in the frame for oscillation about the pin axis and having an end forwardly projecting from the frame, said projecting pin end connected with the fork lift assembly for oscillation of the fork lift assembly about a second axis, through said pin, normal to the first axis.

3. A fork lift mechanism according to claim 1 wherein said pivot means is a spherical bearing affixed to the frame and said lift assembly has a spherical socket mating therewith to permit oscillation of the lift assembly with respect to the frame about both a first axis of said bearing and a second axis of said bearing normal to said first axis.

4. In a fork lift truck, the apparatus comprising:

a frame member having a spherical bearing surface;

a fork lift assembly having a spherical socket disposed in a mating relation to said frame member spherical bearing surface to permit oscillation of said fork lift assembly with respect to said frame about two normally related axes passing through said spherical bearing, said fork lift assembly including sideshifting means; and

a plurality of hydraulic jacks disposed to control oscillation of said fork lift assembly with respect to said fork lift frame about the normally related axes through said spherical bearing.

5. In a fork lift truck having a fork lift assembly adapted for oscillation about both a longitudinal axis of said truck'and a horizontal axis normal to said longitudinal axis, the apparatus comprising:

a fork lift frame having a transverse member horizontally disposed across the front thereof, said tubular member having wear plates on the longitudinally forward extremities thereof;

a spherical mount centrally disposed longitudinally forward of said tubular member between said wear plates;

a fork lift assembly disposed at the front of said frame, said assembly having spherical socket means mating with said socket mount by which said assembly is to be bi-axially oscillated upon two axes through said bearing with respect to said frame, said lift assembly slidably acting on said wear plates and including side-shifting means;

first and second independently controllable hydraulic jacks vertically disposed by means of bi-axial mounts between the ends of said tubular frame member, on either side of said spherical mount, and said fork lift assembly; and

a third hydraulic jack connected in generally horizontal, longitudinal relation between said frame and said lift assembly.

6. The invention of claim 1 wherein the pivot means includes a single bearing member, the two normally related axes intersecting within the single member.

References Cited UNITED STATES PATENTS 1,878,994 9/1932 Abbe 214652 2,870,929 1/1959 Quayle 214-652 3,024,933 3/1962 Albert et al. 214-768 3,182,831 5/1965 Bergmann 214768 HUGO O. SCHULZ, Primary Examiner.

US. Cl. X.R. 2l4652, 730 

